Vehicle lower section structure

ABSTRACT

A vehicle lower section structure includes a battery unit that is disposed below a floor panel, a sliding door that is provided to a side section of a vehicle body, and a lower hinge that is attached to a lower portion of the sliding door, that supports the sliding door with respect to the vehicle body such that the sliding door is capable of sliding in a vehicle front-rear direction, and that is disposed further toward a vehicle upper side than the battery unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119 from Japanese PatentApplication No. 2018-112974, filed on Jun. 13, 2018, the disclosure ofwhich is incorporated by reference herein.

BACKGROUND Technical Field

The present disclosure relates to a vehicle lower section structure.

Related Art

Japanese Patent Application Laid-Open (JP-A) No. 2014-008840 discloses asliding door structure including a sliding door provided to a sidesection of a vehicle body so as to slide in a vehicle front-reardirection. The sliding door is provided with a lower hinge coupled tothe vehicle body to enable the sliding door to be opened and closed. Thelower hinge projects from the sliding door toward the vehicle body side.

In vehicles such as electric cars, a battery unit may be installed belowa floor panel. However, in the structure disclosed in JP-A No.2014-008840, a battery unit is installed below a vehicle floor panel,but no consideration is given to suppressing interference between alower hinge and the battery unit when the lower hinge intrudes toward avehicle width direction inner side in a side collision of the vehicle.

SUMMARY

The present disclosure provides a vehicle lower section structure thatmay protect a battery unit in a side collision of a vehicle including asliding door at a side section of a vehicle body and a battery unitinstalled below a floor panel.

A vehicle lower section structure according to a first aspect includes abattery unit disposed at a vehicle lower side of a floor panel, asliding door provided at a side section of a vehicle body; and a lowerhinge that is disposed further toward a vehicle upper side than thebattery unit, that is attached to a lower portion of the sliding door,and that supports the sliding door with respect to the vehicle body soas to be slidable in a vehicle front-rear direction.

In the vehicle lower section structure according to the first aspect,the battery unit is disposed at the vehicle lower side of the floorpanel. The sliding door is provided to the side section of the vehiclebody, and the lower hinge is attached to the lower portion of thesliding door. The sliding door is supported with respect to the vehiclebody by the lower hinge, such that the sliding door is slidable in thevehicle front-rear direction. The lower hinge is disposed further towardthe vehicle upper side than the battery unit. Thus, the interferencebetween the lower hinge and the battery unit may be suppress, even ifthe lower hinge intrudes toward the vehicle width direction inner sidetogether with the sliding door in a side collision of the vehicle.

In a second aspect of the present disclosure, in the above first aspect,wherein the battery unit may disposed so as to overlap with the lowerhinge as viewed from above the vehicle.

In the vehicle lower section structure according to the second aspect,the battery unit is disposed below the lower hinge, therebyconfiguration components of the battery unit, such as battery cells anda cooling device, may be dispose in a region below the lower hinge.

In a third aspect of the present disclosure, in the above first aspector second aspect, the vehicle body may be provided with a step used whenentering or leaving the vehicle; and a lower guide to guide the lowerhinge may be integrally formed at the step such that the lower hinge ismovable in the vehicle front-rear direction.

In the vehicle lower section structure according to the third aspect,the step and the lower guide are integrally formed to each other, suchthat there is no need to attach a separate lower guide to the step.

In a fourth aspect of the present disclosure, in the above third aspect,wherein an opening/closing device of the sliding, door may be attachedto the step, and the opening/closing device may be disposed furthertoward the vehicle upper side than the battery unit.

In the vehicle lower section structure according to the fourth aspect,interference between the opening/closing device and the battery unit maybe suppressed, even if the opening/closing device of the sliding doorintrudes toward the vehicle width direction inner side in a collisionsuch as a side collision of the vehicle.

In a fifth aspect of the present disclosure, in any one of the firstaspect to the fourth aspect, may further include a side member that isdisposed at a lower face side or an upper thee side of the floor panelso as to configure a closed cross-section with the floor panel and so asto be disposed further toward the vehicle upper side than the batteryunit.

In the vehicle lower section structure according to the fifth aspect,the side member is disposed further toward the vehicle upper side thanthe battery unit, thereby the battery unit may be disposed at thevehicle lower side of the side member.

In a sixth aspect of the present disclosure, in any one of the firstaspect to the fourth aspect, wherein a shock absorbing member may bedisposed further toward a vehicle width direction outer side than thebattery unit.

In the vehicle lower section structure according, to the sixth aspect,if collision load from the vehicle width direction outer side is inputin a side collision, at least part of the collision load is absorbed bythe shock absorbing member. This thereby enables collision load to besuppressed from being input to the battery unit that is further towardthe vehicle width direction inner side than the shock absorbing member.

In a seventh aspect of the present disclosure, in the sixth aspect,wherein a rocker may extend along the vehicle front-rear direction at alower section of the vehicle body, and the shock absorbing member may bedisposed within a cross-section of the rocker.

In the vehicle lower section structure according, to the seventh aspect,the shock absorbing member is disposed within the cross-section of therocker, such that there is no need to secure a separate space in whichto dispose the shock absorbing member between the battery unit and thesliding door.

In an eighth aspect of the present disclosure, in the sixth aspect,wherein a peripheral wall may be provided at a side portion of thebattery unit, the peripheral wall being partitioned into a plurality ofclosed cross-sections arranged along a vehicle vertical direction by anup-down partitioning wall extending in the vehicle width direction, andthe shock absorbing member may be disposed at the vehicle widthdirection outer side of the peripheral wall, and is partitioned into aplurality of closed cross-sections arranged along the vehicle widthdirection by a left-right partitioning wall extending in the vehiclevertical direction.

In the vehicle lower section structure according to the eighth aspect,the shock absorbing member is partitioned in the vehicle width directionby the left-right partitioning wall, such that the respective closedcross-sections deform in a side collision, shock absorbing performancemay be improved. The peripheral wall of the battery unit is partitionedinto upper and lower closed cross-sections by the up-down partitioningwall, thereby load-withstand performance with respect to load acting inthe vehicle width direction may be improved.

As described above, in the vehicle lower section structure of the firstaspect, the battery unit is protected in a collision such as a sidecollision in a vehicle including the sliding door at the side section ofthe vehicle body and mounted with the battery unit below the floorpanel.

In the vehicle lower section structure of the second aspect, the batteryinstallation capacity is increased without increasing the width of thevehicle, in comparison to configurations in which the battery unit isdisposed further to the vehicle width direction inner side than thelower hinge as viewed from above the vehicle.

In the vehicle lower section structure of the third aspect, the numberof components is reduced.

In the vehicle lower section structure of the fourth aspect, collisionload is suppressed from being input from the opening/closing device ofthe sliding door to the battery unit in a collision such as a sidecollision.

In the vehicle lower section structure of the fifth aspect, the batteryinstallation capacity is increased without increasing the width of thevehicle, in comparison to configurations in which the side memberextends further toward the vehicle lower side than an upper end portionof the battery unit.

In the vehicle lower section structure of the sixth aspect, theprotection performance of the battery unit in a side collision isimproved.

In the vehicle lower section structure of the seventh aspect, space issaved while improving the protection performance of the battery unit.

In the vehicle lower section structure of the eighth aspect, the shockabsorbing performance by the shock absorbing member is improved, and theload-withstand performance of the battery unit is also improved.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiment of the present disclosure will be described indetail based on the following figures, wherein:

FIG. 1 is a cross-section illustrating a lower section of a vehicleapplied with a vehicle lower section structure according to an exemplaryembodiment;

FIG. 2 is a perspective view illustrating a rear section of a vehicleapplied with a vehicle lower section structure according to an exemplaryembodiment, as viewed from an outer side;

FIG. 3 is a cross-section corresponding to FIG. 1, illustrating amodified example of a vehicle lower section structure according to anexemplary embodiment;

FIG. 4 is a cross-section corresponding to FIG. 1, illustrating a lowersection of a vehicle applied with a vehicle lower section structureaccording to a reference example; and

FIG. 5 is a cross-section corresponding to FIG. 1, illustrating a lowersection of a vehicle applied with a vehicle lower section structureaccording to a comparative example.

DETAILED DESCRIPTION

Explanation follows regarding a vehicle lower section structureaccording to an exemplary embodiment, with reference to the drawings.Note that in the respective drawings, the arrow UP indicates a vehicleupper side, the arrow FR indicates a vehicle front side, and the arrowLH indicates a vehicle width direction (left-right direction) left side,as appropriate. In the following explanation, unless specifically statedotherwise, reference to the front, rear, up, down, left, and rightdirections refers to the front and rear in a vehicle front-reardirection, up and down in a vehicle vertical direction, and left andright when facing in the direction of travel.

As illustrated in FIG. 1, a vehicle body 11 of a vehicle 10 applied withthe vehicle lower section structure according to the present exemplaryembodiment includes a floor panel 12 configuring a floor surface of avehicle cabin. The floor panel 12 extends in the vehicle width directionand the vehicle front-rear direction with its plate thickness directionalong the vehicle vertical direction. A floor carpet 14 is laid on anupper face of the floor panel 12. A side member 16 is provided at alower face side of the floor and 12.

The side member 16 is formed with a substantially hat-shapedcross-section profile opening toward the vehicle upper side as viewedalong the vehicle front-rear direction, and includes flanges 16A at bothvehicle width direction ends of the side member 16 that are overlaid onand joined to the lower face of the floor panel 12. A closedcross-section is thus configured between the side member 16 and thefloor panel 12. The side member 16 extends along the vehicle front-reardirection so as to reinforce the floor panel 12.

A battery unit 18 is disposed below the floor panel 12. The battery unit18 is provided spanning the entire region below the floor panel 12. Theside member 16 is thus disposed at the vehicle upper side of the batteryunit 18 and part of the battery unit 18 is disposed overlapping the sidemember 16 as viewed from the vehicle upper side.

The battery unit 18 includes a case 20 serving as an outer shell. Pluralbattery cells, a wire harness, a cooling device, and so on, none ofwhich are illustrated in the drawings, are housed in the case 20. Drivepower from the battery unit 18 can be supplied to a motor, notillustrated in the drawings.

The case 20 is configured including a bottom wall 22, a peripheral wall24, and a cover 26. The bottom wall 22 extends in the vehicle widthdirection and the vehicle front-rear direction with its plate thicknessdirection along the vehicle vertical direction. Both vehicle widthdirection end portions of the bottom wall 22 are fastened to rockers 34,described later, by bolts 28 and nuts 30. Although not illustrated inthe drawings, the bottom wall 22 is fastened to the rockers 34 atpredetermined spacings along the vehicle front-rear direction.

The peripheral wall 24 projects upward from an outer peripheral portionof the bottom wall 22. The peripheral wall 24 is formed in a frame shapefollowing the outer peripheral portion of the bottom wall 22 in planview, and is formed by extrusion molding a metal such as aluminum as anexample in the present exemplary embodiment. A portion of the peripheralwall 24 configuring a side portion of time battery unit 18 has a closedcross-section structure as viewed along the vehicle front-reardirection, and is partitioned into plural (two) closed cross-sections24B, 24C arranged along the vehicle vertical direction by an up-downpartitioning wall 24A extending in the vehicle width direction. Notethat although not illustrated in the drawings, the right side of thevehicle has a similar structure.

The cover 26 is provided to an upper portion of the battery unit 18. Thecover 26 is formed in a substantially rectangular shape corresponding tothe external profile of the peripheral wall 24, with its plate thicknessdirection along the vehicle vertical direction. An outer peripheral endportion of the cover 26 is fastened to an upper face of the peripheralwall 24 by bolts 32.

The rockers 34 are provided at the vehicle width direction outer sidesof the battery unit 18 configured as described above. The rockers 34 arepositioned at a lower section of the vehicle body 11, and are eachconfigured including a rocker outer panel 36 and a rocker inner panel38.

The rocker outer panel 36 is positioned at the vehicle width directionouter side, and is formed in substantially a crank shape as viewed alongthe vehicle front-rear direction. More specifically, the rocker outerpanel 36 extends from an outer side upper flange 36A at an upper endportion toward the vehicle lower side, and a lower portion of the rockerouter panel 36 is bent toward the vehicle width direction inner side. Anouter side lower flange 36B extends from a vehicle width direction innerside end portion of the rocker outer panel 36 toward the vehicle lowerside.

The rocker inner panel 38 is positioned at the vehicle width directioninner side, and is formed with a substantially hat-shaped cross-sectionprofile opening toward the vehicle width direction outer side as viewedalong the vehicle front-rear direction. An inner side upper flange 38Aextending in the vehicle vertical direction is formed to an upper endportion of the rocker inner panel 38. The inner side upper flange 38A isjoined to the outer side upper flange 36A of the rocker outer panel 36in a superimposed state. A weather strip 41 is attached to the outerside upper flange 36A and the inner side upper flange 38A. The weatherstrip 41 forms a seal with respect to a sliding door 50, describedlater.

An inner side lower flange 38B extending in the vehicle verticaldirection is formed to a lower end portion of the rocker inner panel 38.The inner side lower flange 38B is joined to the outer side lower flange36B of the rocker outer panel 36 in a superimposed state. The rocker 34is configured with a closed cross-section structure in this manner.

A rocker molding 40 is provided at an outer side of the rocker 34. Therocker molding 40 is formed from resin, and is attached to the rockerouter panel 36 using clips or the like, not illustrated in the drawings,so as to cover a lower portion of the rocker outer panel 36 from thevehicle width direction outer side.

A shock absorbing member 42 is disposed inside the closed cross-sectionof the rocker 34. The shock absorbing member 42 is disposed between thebattery unit 18 and the sliding door 50, and extends along the vehiclefront-rear direction following the rocker 34. In the present exemplaryembodiment, as an example, the shock absorbing member 42 is formed byextrusion molding a metal such as aluminum.

The shock absorbing member 42 has a closed cross-section structure asviewed along the vehicle front-rear direction, and is partitioned intoplural (three) closed cross-sections 42B, 42C, 42D arranged along thevehicle width direction by two left-right partitioning walls 42Aextending in the vehicle vertical direction.

A step under-panel 44 is provided between the floor panel 12 and therocker 34. The floor panel 12 and the rocker 34 are coupled together bythe step under-panel 44. An upper end portion of the step under-panel 44is configured by an upper flange 44. A bent so as to follow the lowerface of the floor panel 12, and the upper flange 44A is joined to thefloor panel 12.

The step under-panel 44 extends from the upper flange 44A toward thevehicle lower side, and then extends toward the vehicle width directionouter side following the cover 26 of the battery unit 18. The stepunder-panel 44 then extends from a position further toward the vehiclewidth direction outer side than the peripheral wall 24 of the batteryunit 18 toward the vehicle lower side, and a lower end portion of thestep under-panel 44 is configured by a lower flange 44B that is bent soas to follow the rocker inner panel 38. The lower flange 44B issuperimposed on and joined to the rocker inner panel 38. In this manner,the step under-panel 44 is formed in a shape that avoids the batteryunit 18.

A step 46 that is used when an occupant enters or leaves the vehicle isattached to the step under-panel 44. The step 46 is formed with asubstantially L-shaped profile as viewed along the vehicle front-reardirection, and a lower end portion of the step 46 is configured by afixing portion 46A that is bent so as to follow the step under-panel 44.The fixing portion 46A is fastened to the step under-panel 44 by bolts47 and nuts 49.

The step 46 extends from the fixing portion 46A toward the vehicle upperside, and then extends toward the vehicle width direction outer side. Astep body 46B extending in the vehicle width direction is provided withreinforcing ribs 46C. Plural of the ribs 46C are provided (five areillustrated in FIG. 1) projecting from the step body 46B toward thevehicle upper side.

A lower face side of the step body 46B is provided with a lower guide48. The lower guide 48 is configured including a pair of left and rightguide tabs 48A projecting from the step body 46B toward the vehiclelower side. The guide tabs 48A are integrally formed to the step body46B (the step 46). Each of the pair of guide tabs 48A extend in thevehicle front-rear direction so as to follow the step body 46B, and aguide roller 62 of a lower hinge 56, described later, enters between thepair of guide tabs 48A. In this manner, the lower guide 48 guides thelower hinge 56 such that the lower hinge 56 is capable of moving in thevehicle front-rear direction.

A resin scuff plate 45 is provided above the step 46. The scuff plate 45extends from a vehicle width direction end portion of the floor panel 12as far as a vehicle width direction end portion of the step body 46B,and is attached to the step 46 by clips or the like, not illustrated inthe drawings.

An opening/closing device 68 of the sliding door 50 is attached to thestep 46. The opening/closing device 68 is a component including a motor,pulleys, and the like needed in order to open and close the sliding door50 automatically. The opening/closing device 68 is disposed on the stepunder-panel 44. Namely, the opening/closing device 68 is disposedfurther toward the vehicle upper side than the battery unit 18.

Sliding Door 50 Configuration

Explanation follows regarding configuration of the sliding door 50. Asillustrated in FIG. 2, the sliding door 50 is provided at a side sectionof the vehicle body 11, and is capable of opening and closing off anopening 11A thrilled in the side section of the vehicle body 11 for anoccupant to enter or leave the vehicle.

The vehicle body 11 is provided with an upper guide 72, a center guide75, and the lower guide 48. The upper guide 72 is provided at an uppersection of the vehicle body 11 and extends along the vehicle front-reardirection. The center guide 75 is provided at a vehicle verticaldirection intermediate section of the vehicle body 11, and extends alongthe vehicle front-rear direction. The lower guide 48 is provided at alower section of the vehicle body 11, and extends along the vehiclefront-rear direction.

An upper hinge 74 is attached to an upper portion of the sliding door50. A guide roller 74A provided to the upper hinge 74 engages with theupper guide 72. A center hinge 76 is attached to a vehicle verticaldirection intermediate portion of the sliding door 50. A guide roller76A provided to the center hinge 76 is engaged with the center guide 75.The lower hinge 56 is attached to a lower portion of the sliding door50. The guide roller 62 provided to the lower hinge 56 engages with thelower guide 48. In this manner, the sliding door 50 is supported so asto be capable of moving in the vehicle front-rear direction with respectto the vehicle body 11. Note that in FIG. 2, for ease of explanation,the respective guides and guide rollers are illustrated as if separatedfrom each other; however, in reality, the guide rollers enter theguides.

As illustrated in FIG. 1, the sliding door 50 is configured including adoor outer panel 52 on the vehicle width direction outer side and a doorinner panel 54 on the vehicle width direction inner side. Peripheraledge portions of the door outer panel 52 and the door inner panel 54 arejoined together by hemming.

The lower hinge 56 is attached to the lower portion of the sliding door50. The lower hinge 56 is attached to a vehicle width direction innerside face of the door inner panel 54, and is formed in substantially anL-shape as viewed along the vehicle front-rear direction. The lowerhinge 56 is configured including a hinge body 58, a base 60, the guideroller 62, and a load roller 64.

The hinge body 58 is configured including a fixing portion 58A extendingin the vehicle vertical direction so as to follow the door inner panel54, and a base attachment portion 58B extending from a lower end portionof the fixing portion 58A toward the vehicle width direction inner side.

The fixing portion 58A is formed with a substantially hat-shapedcross-section profile opening toward the vehicle width direction outerside, and is fastened to the door inner panel 54 by bolts 65 and nuts67. The base attachment portion 58B is formed with a substantiallyhat-shaped cross-section profile opening toward the vehicle lower side,and extends as far as below a leading end portion of the step 46. Oneend portion of a coupling member 66 is fixed to a lower face side of thebase attachment portion 58B by bolts 69 and nuts 70.

The coupling member 66 is an elongated member extending in the vehiclewidth direction with its plate thickness direction along the vehiclevertical direction. The base 60 is attached to another end portion ofthe coupling member 66 by a pin 71 such that the base 60 is capable ofswinging.

The base 60 extends from the coupling member 66 toward the vehicle widthdirection inner side. A shaft 61 with its axial direction along thevehicle vertical direction is provided at a leading end portion of thebase 60. The guide roller 62 is rotatably attached to the shaft 61, andthe guide roller 62 enters between the pair of guide tabs 48Aconfiguring the lower guide 48.

The base 60 is also provided with a shaft 63 with its axial directionalong the vehicle front-rear direction. The load roller 64 is rotatablyattached to the shaft 63. The load roller 64 contacts the stepunder-panel 44, and the lower hinge 56 is supported by the stepunder-panel 44 through the load roller 64.

As described above, the sliding door 50 is supported by the lower hinge56 so as to be capable of sliding in the vehicle front-rear directionwith respect to the vehicle body 11. Note that the lower hinge 56 isdisposed further toward the vehicle upper side than the battery unit 18.Namely, the lower hinge 56 and the battery unit 18 are disposed atpositions that do not overlap as viewed along the vehicle widthdirection.

The battery unit 18 is disposed at a position overlapping the lowerhinge 56 as viewed from above the vehicle. In the present exemplaryembodiment, in a state in which the sliding door 50 is closed, the base60 of the lower hinge 56 is disposed above the peripheral wall 24 of thebattery unit 18. The base 60 and the peripheral wall 24 thereforeoverlap as viewed from above the vehicle.

Operation

Explanation follows regarding operation of the present exemplaryembodiment.

In the vehicle 10 applied with the vehicle lower section structureaccording to the present exemplary embodiment, the lower hinge 56 isdisposed further toward the vehicle upper side than the battery unit 18.Accordingly, even if the lower hinge 56 intrudes toward the vehiclewidth direction inner side together with the sliding door 50 in a sidecollision of the vehicle, the lower hinge 56 is suppressed fromcontacting the battery unit 18. Namely, interference between the lowerhinge 56 and the battery unit 18 is suppressed, and the battery unit 18is thereby protected.

Explanation follows regarding the above operation, drawing comparisonsto a comparative example illustrated in FIG. 5. Note that configurationssimilar to those of the present exemplary embodiment are allocated thesame reference numerals, and explanation thereof is omitted asappropriate. As illustrated in FIG. 5, a vehicle body 202 of a vehicle200 applied with a vehicle lower section structure of the comparativeexample is provided with the floor panel 12 configuring the floorsurface of the vehicle cabin, and side members 214 are provided at alower face side of the floor panel 12.

Each of the side members 214 is formed with a substantially hat-shapedcross-section profile opening toward the vehicle upper side as viewedalong the vehicle front-rear direction, and flanges 214A on both vehiclewidth direction sides of the side member 214 are superimposed on andjoined to the lower face of the floor panel 12. Note that the sidemember 214 of the comparative example is formed with a greater vehiclevertical direction length than the side member 16 of the presentexemplary embodiment.

A battery unit 204 is disposed below the floor panel 12. The batteryunit 204 is attached to the side member 214.

A case 206 of the battery unit 204 is configured including a bottom wall208, a peripheral wall 210, and a cover 212. The bottom wall 208 extendsin the vehicle width direction and the vehicle front-rear direction withits plate thickness direction along the vehicle vertical direction. Bothvehicle width direction end portions of the bottom wall 208 are fastenedto the respective side members 214 by bolts 216 and nuts 218.

The peripheral wall 210 is formed in a frame shape following an outerperipheral portion of the bottom wall 208. A portion of the peripheralwall 210 configuring a side portion of the battery unit 204 has a closedcross-section structure as viewed along the vehicle front-reardirection, and is partitioned into plural (two) closed cross-sections210B, 210C arranged along the vehicle vertical direction by an up-downpartitioning wall 210A extending in the vehicle width direction.

The cover 212 is formed in a substantially rectangular shapecorresponding to the external profile of the peripheral wall 210, withits plate thickness direction along the vehicle vertical direction. Anouter peripheral end portion of the cover 212 is fastened to an upperface of the peripheral wall 210.

Note that an upper portion of the battery unit 204 of the comparativeexample is disposed at a position overlapping the lower hinge 56 asviewed along the vehicle width direction. Namely, the battery unit 204is disposed on an extension line of the base attachment portion 58B ofthe lower hinge 56 extending toward the vehicle width direction innerside.

Moreover, the upper portion of the battery unit 204 of the comparativeexample is disposed at a position overlapping the step 46 as viewedalong the vehicle width direction. Accordingly, in the vehicle 200applied with the vehicle lower section structure of the comparativeexample, if load toward the vehicle width direction inner side acts onthe sliding door 50 in a side collision, the sliding door 50 and thelower hinge 56 intrude toward the vehicle width direction inner side.This might cause the lower hinge 56 to interfere with the battery unit204 through the side member 214.

By contrast, in the vehicle 10 applied with the vehicle lower sectionstructure of the present exemplary embodiment, as illustrated in FIG. 1,the lower hinge 56 and the battery unit 18 are disposed at positionsthat do not overlap each other as viewed along the vehicle widthdirection. Interference between the lower hinge 56 and the battery unit18 in a side collision is accordingly suppressed, and the battery unit18 is thereby protected.

Moreover, in the present exemplary embodiment, the vehicle widthdirection end portion of the battery unit 18 is disposed at the vehiclelower side of the lower hinge 56. Namely, the battery unit 18 and thelower hinge 56 are disposed so as to overlap each other as viewed fromabove the vehicle. Accordingly, configuration components of the batteryunit 18, such as the battery cells and the cooling device, can bedisposed in a region below the lower hinge 56, thereby increasing thebattery installation capacity without increasing the width of thevehicle, in comparison to configurations in which the battery unit 18 isdisposed further to the vehicle width direction inner side than thelower hinge 56 as viewed from above the vehicle.

Moreover, in the present exemplary embodiment, the step 46 and the lowerguide 48 are integrally formed to each other. Accordingly, there is noneed to attach a separate lower guide 48 to the step body 46B. This alsoreduces the number of components. In particular, in the presentexemplary embodiment, the step 46 and the lower guide 48 are positionedfurther toward the vehicle upper side than the lower hinge 56, therebysuppressing interference between the step 46 and the battery unit 18 ina side collision of the vehicle.

In the present exemplary embodiment, the opening/closing device 68 ofthe sliding door 50 is also disposed further toward the vehicle upperside than the battery unit 18. Accordingly, interference between theopening/closing device 68 and the battery unit 18 is suppressed, even ifthe opening/closing device 68 intrudes toward the vehicle widthdirection inner side in a side collision of the vehicle 10.

Moreover, in the present exemplary embodiment, the side member 16 isprovided at the lower face side of the floor panel 12, but the sidemember 16 is also disposed further toward the vehicle upper side thanthe battery unit 18. This thereby enables the battery unit 18 to bedisposed at the vehicle lower side of the side member 16, therebyincreasing the battery installation, capacity without increasing thewidth of the vehicle, in comparison to configurations in which the sidemember 16 extends further toward the vehicle lower side than the upperend portion of the battery unit 18.

Moreover, in the present exemplary embodiment, the shock absorbingmember 42 is disposed between the battery unit 18 and the sliding door50. Accordingly, if collision load is input to the sliding door 50 in aside collision, at least part of the collision load can be absorbed bythe shock absorbing member 42. This thereby enables collision load to besuppressed from being input to the battery unit 18 that is furthertoward the vehicle width direction inner side than the shock absorbingmember 42, thereby improving the protection performance of the batteryunit 18 in a side collision.

In particular, in the present exemplary embodiment, the shock absorbingmember 42 is disposed within the cross-section of the rocker 34. Thereis accordingly no need to secure a separate space in which to disposethe shock absorbing member 42. Namely, the shock absorbing member 42 canbe disposed while securing a space between the battery unit 18 and thesliding door 50.

Moreover, in the present exemplary embodiment, the closed cross-sectionof the shock absorbing member 42 is partitioned in the vehicle widthdirection by the left-right partitioning walls 42A. Accordingly, in aside collision, the closed cross-section 42D on the collision side iscrushed first, absorbing shock, after which the closed cross-section 42Cis crushed. The closed cross-section 42B is then crushed, such that theclosed cross-sections can be crushed sequentially, enabling the shockabsorbing performance to be improved.

The peripheral wall 24 of the battery unit 18 is partitioned into upperand lower closed cross-sections by the up-down partitioning wall 24A.Namely, since the up-down partitioning wall 24A extends in the vehiclewidth direction, load-withstand performance with respect to load actingin the vehicle width direction in a side collision can be improved. Thisthereby enables the shock absorbing performance by the shock absorbingmember 42 to be improved, and also enables the load-withstandperformance of the battery unit 18 to be improved.

Note that in the exemplary embodiment described above, the shockabsorbing member 42 is disposed within the cross-section of the rocker34. However, there is no limitation thereto, and the structure of amodified example illustrated in FIG. 3 may be adopted.

MODIFIED EXAMPLE

As illustrated in FIG. 3, in the present modified example, a shockabsorbing member 78 is provided above the rocker 34. More specifically,the shock absorbing member 78 is disposed between the battery unit 18and the sliding door 50, and is attached to the step under-panel 44.

A protrusion 44C that protrudes toward the vehicle upper side is formedto the lower flange 44B of the step under-panel 44. The shock absorbingmember 78 is fixed onto the protrusion 44C. An upper face of theprotrusion 44C extends substantially in a horizontal direction, and theshock absorbing member 78 is supported by the protrusion 44C and avertical wall of the step under-panel 44 (a portion extending from avehicle width direction inner side end portion of the lower flange 44Btoward the vehicle upper side). The shock absorbing member 78 is therebysuppressed from tilting.

The shock absorbing member 78 has a similar profile to the shockabsorbing member 42 of the above exemplary embodiment. Namely, the shockabsorbing member 78 has a closed cross-section structure as viewed alongthe vehicle front-rear direction, and is partitioned into plural (three)closed cross-sections 78B, 78C, 78D arranged along the vehicle widthdirection by two left-right partitioning walls 78A extending in thevehicle vertical direction.

In the present modified example, similarly to in the above exemplaryembodiment, at least part of the shock in a side collision can beabsorbed by the shock absorbing member 78. Moreover, since the shockabsorbing member 78 is provided at the exterior of the rocker 34, theshock absorbing member 78 can be attached after the rocker 34 has beenformed.

Explanation has been given regarding vehicle lower section structuresaccording to the above exemplary embodiment and the modified example.However, obviously various configurations may be implemented within arange not departing from the spirit of the present disclosure. Forexample, a step including a shock absorbing structure may be employed.In such cases, shock can be absorbed by both the shock absorbing member42 and the step in a side collision of the vehicle 10. A structure thatis crushed when input with collision load along the vehicle widthdirection may also be employed as such a shock absorbing structure.

Moreover, in the above exemplary embodiment and the modified example, ashock absorbing member provided with three closed cross-sectionsarranged along the vehicle width direction is employed. However, thereis no limitation thereto, and a shock absorbing member with even moreclosed cross-sections may be employed. Moreover, configuration may beapplied in which the closed cross-section of the rocker 34 is milledwith a shock absorbing member formed of foamed resin or the like insteadof the shock absorbing member 42.

Moreover, the vehicle lower section structure according to the aboveexemplary embodiment may be interpreted from another viewpoint. Forexample, the issue addressed by (the object of) the vehicle lowersection structure according to the present exemplary embodiment may beinterpreted as being to “increase battery installation capacity withoutincreasing the width of the vehicle”.

When the issue is interpreted in the above manner, the disclosureserving as a manner of addressing this issue may, for example, bedescribed as follows:

A vehicle lower section structure including:

a battery unit that is disposed at a vehicle lower section;

a sliding door that is provided to a side section of a vehicle body; and

a lower hinge that extends in a vehicle width direction, and thatsupports the sliding door with respect to the vehicle body such that thesliding door is capable of sliding in a vehicle front-rear direction,

-   -   the lower hinge being disposed either further toward a vehicle        upper side than the battery unit or further toward a vehicle        lower side than the battery unit.

In the above configuration, since the lower hinge extending in thevehicle width direction is disposed further toward the vehicle upperside or the vehicle lower side than the battery unit, the battery unitcan be enlarged toward the vehicle width direction outer side. As aresult, the battery installation capacity can be increased withoutincreasing the width of the vehicle, in comparison to configurations inwhich the lower hinge and the battery unit are disposed so as to overlapeach other as viewed along the vehicle width direction.

Explanation follows regarding a structure provided with theconfiguration described above as a reference example, with reference tothe drawings. Note that content similar to that of the present exemplaryembodiment is allocated the same reference numerals, and explanationthereof is omitted as appropriate.

REFERENCE EXAMPLE

As illustrated in FIG. 4, a vehicle body 102 of a vehicle 100 appliedwith a vehicle lower section structure according to the referenceexample includes a floor panel 104 configuring a floor surface of avehicle cabin. The floor panel 104 extends in the vehicle widthdirection and the vehicle front-rear direction with its plate thicknessdirection along the vehicle vertical direction. A side member 106 isprovided at a lower face side of the floor panel 104.

The side member 106 is formed with a substantially hat-shapedcross-section profile opening toward the vehicle upper side as viewedalong the vehicle front-rear direction, and blames 106A on both vehiclewidth direction sides of the side member 106 are superimposed on andjoined to the lower face of the floor panel 104.

The step under-panel 44 is provided between the side member 106 and thesliding door 50. An upper end portion of the step under-panel 44configures the upper flange 44A that is bent so as to follow the lowerface of the floor panel 104. The upper flange 44A is joined to the floorpanel 104.

The step under-panel 44 extends from the upper flange 44A toward thevehicle lower side, and is bent toward the vehicle width direction outerside at a height corresponding to a vehicle vertical directionintermediate portion of the side member 106. The step under-panel 44then extends toward the vehicle lower side from a position furthertoward the vehicle width direction outer side than the load roller 64 ofthe lower hinge 56, and a lower end portion of the step under-panel 44configures the lower flange 44B that is bent so as to follow the rockerinner panel 38. The lower flange 44B is superimposed on and joined tothe rocker inner panel 38.

A step 110 used when an occupant enters or leaves the vehicle isattached to the step under-panel 44. The step 110 is formed with asubstantially L-shaped profile as viewed along the vehicle front-reardirection, and a lower end portion of the step 110 is configured by afixing portion 110A that is bent so as to follow the step under-panel44. The fixing portion 110A is fastened to the step under-panel 44 bybolts 47 and nuts 49.

The step 110 extends from the fixing portion 110A toward the vehicleupper side, and then extends toward the vehicle width direction outerside. A pair of left and right guide tabs 112A project toward thevehicle lower side from a step body 110B extending in the vehicle widthdirection. The guide tabs 112A configure a lower guide 112.

The pair of guide tabs 112A are integrally formed to the step body 110B(the step 110), and extend along the vehicle front-rear directionfollowing the step body 110B. The guide roller 62 of the lower hinge 56enters between the pair of guide tabs 112A. The lower guide 112 therebysupports the lower hinge 56 (the sliding door 50) with respect to thevehicle body 102 such that the lower hinge 56 is capable of sliding inthe vehicle front-rear direction.

The battery unit 18 is fixed to an upper face side of the step body110B, such that the battery unit 18 is disposed above the floor panel104. Accordingly the side member 106 is disposed at the vehicle lowerside of the battery unit 18, and part of the battery unit 18 overlapsthe side member 106 as viewed from above the vehicle.

The battery unit 18 is disposed in a vehicle lower section, and includesthe case 20 serving as an outer shell. Plural battery cells, a wireharness, a cooling device, and the like, none of which are illustratedin the drawings, are housed in the case 20. Drive power from the batteryunit 18 can be supplied to a motor, not illustrated in the drawings.

The case 20 is configured including the bottom wall 22, the peripheralwall 24, and the cover 26. The bottom wall 22 extends in the vehiclewidth direction and the vehicle front-rear direction with its platethickness direction along the vehicle vertical direction. Both vehiclewidth direction end portions of the bottom wall 22 are fastened to thecorresponding step body 110B by bolts 114. A spacer 116 is attachedbetween the bottom wall 22 and the corresponding step body 110B suchthat a gap is provided between the bottom wall 22 and the step body110B.

Note that the step 110 is disposed further toward the vehicle lower sidethan the battery unit 18. Namely, the step 110 is disposed at a positionthat does not overlap the battery unit 18 as viewed along the vehiclewidth direction.

Moreover, the battery unit 18 is disposed at a position overlapping thestep 110 and the lower hinge 56 as viewed from above the vehicle. In thepresent exemplary embodiment, the base 60 of the lower hinge 56 and thelower guide 112 are disposed below the peripheral wall 24 of the batteryunit 18 in a state in which the sliding door 50 has been closed.

Due to the above configuration, the step 110 and the lower hinge 56extending in the vehicle width direction are disposed further toward thevehicle lower side than the battery unit 18, thereby enabling thebattery unit 18 to be enlarged toward the vehicle width direction outerside. This thereby enables the battery installation capacity to beincreased without increasing the width of the vehicle, in comparison toconfigurations in which the step 110 and the battery unit 18 aredisposed so as to overlap each other as viewed along the vehicle widthdirection.

Note that in the reference example, the shock absorbing member 42 isprovided within the rocker 34 in order to improve collision-withstandperformance in a side collision. Moreover, a cross member 108 extendingin the vehicle width direction is disposed between the rockers 34, andboth end portions of the cross member 108 are respectively joined to theleft and right rockers 34 to achieve a structure in which collision loadis readily transmitted toward the non-collision side.

What is claimed is:
 1. A vehicle lower section structure comprising: abattery unit disposed at a vehicle lower side of a floor panel; asliding door provided at a side section of a vehicle body; and a lowerhinge that is disposed further toward a vehicle upper side than thebattery unit, that is attached to a lower portion of the sliding door,and that supports the sliding door with respect to the vehicle body soas to be slidable in a vehicle front-rear direction.
 2. The vehiclelower section structure of claim 1, wherein the battery unit is disposedso as to overlap with the lower hinge as viewed from above the vehicle.3. The vehicle lower section structure of claim 1, wherein: the vehiclebody is provided with a step used when entering or leaving the vehicle;and a lower guide to guide the lower hinge is integrally formed at thestep such that the lower hinge is movable in the vehicle front-reardirection.
 4. The vehicle lower section structure of claim 3, wherein:an opening/closing device of the sliding door is attached to the step;and the opening/closing device is disposed further toward the vehicleupper side than the battery unit.
 5. The vehicle lower section structureof claim 1, further comprising a side member that is disposed at a lowerface side or an upper face side of the floor panel so as to configure aclosed cross-section with the floor panel and so as to be disposedfurther toward the vehicle upper side than the battery unit.
 6. Thevehicle lower section structure of claim 1, wherein a shock absorbingmember is disposed further toward a vehicle width direction outer sidethan the battery unit.
 7. The vehicle lower section structure of claim6, wherein: a rocker extends along the vehicle front-rear direction at alower section of the vehicle body; and the shock absorbing member isdisposed within a cross-section of the rocker.
 8. The vehicle lowersection structure of claim 6, wherein: a peripheral wall is provided ata side portion of the battery unit, the peripheral wall beingpartitioned into a plurality of closed cross-sections arranged along avehicle vertical direction by an up-down partitioning wall extending inthe vehicle width direction; and the shock absorbing member is disposedat the vehicle width direction outer side of the peripheral wall, and ispartitioned into a plurality of closed cross-sections arranged along thevehicle width direction by a left-right partitioning wall extending inthe vehicle vertical direction.